The body is organized into six major muscle groups that structure most strength training programs: chest (pectorals), back (latissimus dorsi, trapezius, rhomboids), shoulders (deltoids), arms (biceps, triceps), legs (quadriceps, hamstrings, glutes, calves), and core (abdominals, obliques, erector spinae). Understanding these regions helps in selecting exercises that target specific goals, whether aesthetic, athletic, or functional.
Exercises fall along a spectrum from compound to isolation movements. A compound exercise works multiple joints and muscle groups simultaneously, like the squat or bench press, allowing heavier loads and producing a greater systemic hormonal response. An isolation exercise targets a single joint and muscle group, such as a bicep curl or leg extension. Compound lower-body exercises such as the back squat, deadlift, and lunge engage the quads, hamstrings, glutes, and core to varying degrees, while isolation movements for the arms such as the bicep curl, tricep pushdown, and hammer curl focus exclusively on the elbow joint.
To describe training, lifters use standard terminology. A rep (repetition) is one complete movement of an exercise through its full range of motion. A set is a group of consecutive reps performed without rest, so ten push-ups in a row counts as one set of ten. Training volume is typically calculated as \( \text{sets} \times \text{reps} \times \text{weight} \), and higher volume generally promotes greater muscle growth until diminishing returns or overtraining set in. Training intensity refers to the load used relative to your one-rep max (1RM), expressed as a percentage such as 80% of 1RM, where heavier loads mean fewer reps per set.